typeList = ["lambert","standardSurface","surfaceShader","phong","blinn"]
for  type in  typeList:
	all_lambertList =cmds.ls(type=type)
	print all_lambertList
	for  lambert in all_lambertList: 
		fileName = cmds.defaultNavigation (defaultTraversal=1, destination = lambert + ".outColor")
		print(fileName)
		if fileName :
			mel.eval('generateUvTilePreview '  + fileName[0])